def describe_pet(pet_name, animal_type="dog"):
    """显示宠物的信息"""
    print("\nI have a " + animal_type + ".")
    print("My " + animal_type + "'s name is " + pet_name.title() + ".")


describe_pet('hamster', 'harry')
describe_pet('dog', 'willie')
describe_pet(animal_type='hamster', pet_name='harry')

describe_pet(pet_name="hunter", animal_type="cat")
describe_pet(pet_name="hunter")
describe_pet("hill")
